Electric clock



L. E. SHAW.

ELECTBIOCLOCK. APPLICATION FILED Dsc. 8.` 1919.

1,400,832 Patented Dec. 20, 1921.

W lrwl A TTORNE Y.

UNITED STATES PATENT OFFICE.

LOUIS E. SHAW, OF EAST ORANGE, NEW JERSEY. l

ELECTRIC CLOCK.

Spevcication ot Letters Patent.

Patented Dec. 20, 1921.

Application nled December 8, 1919. Serial No. 343,194.

description of the invention, sucli as will enable others, skilled in theartto which it appertains to make and use the same.

he present invention relates to .electric clocks, and particularly to those having an electromagnetically-operative actuatin mechanism for the movement thereof, including a spring which is wound intermittently for subsequently actuating the movement. v V

In prior clocks of this kind, the movement is not magnetically screened fromthe electromagnet, so that the magnetism thereof is liableto affect the 'accurate working of the clock. In accordance with one part of my invention, the electromagnet has a continuous core, preferably of annular form surrounding 'the movementv and being .of trough section with the flanges directed outwardly of the base and inclosing the energizing winding. Thus substantially all the lines of force external of the-core extend outwardly of the movement between the poles formed by the flanges of the core. Be-

sides magnetically screening the movement in this way, this form of magnet has continuous poles nicely providing for the actuation of a number of armatures at convem'ent places around its periphery, and mechanically protects the energizing wind- Irrespective of the form of the core of the electromagnet, my invention comprehends, as another of its parts, two armatures which are connected to springs and whichare oppositely pivoted, that is which extend in oppositepdi'rections from their pivots. This arrangement tends to eliminate the disturbing e ects of shock and vibration to which the clock i's'subjected when mounted on a moving vehicle,l such as an automobile. The' result may be enhanced by havingthe armatures diametrica-lly disposed to each other, and by extending the pringsin opposite directions from their fixed connections and connecting them at diametrically opposite points to a pawl-carrying member which is Journaled on the arbor of the movement.. By substantially balancing the pawlcarrying member on both sides of the arbor, the effect of shock or vibration to the clock is further neutralized on the/ratchet with which the pawls engage for actuating the movement.

The invention further com rehends, as another. of its parts, coperaltive electric contacts arranged in the circuit between the g energizing winding of the electromagnet and the source ofcurrent, the movable one of the contacts being mounted on a pivoted arm whichcarriesv an armature of the electromagnet and which extends into the path of the movement of a movable part of the electromagnetically-operative actuating mechanism of the cloc rThus as soon as the contacts close, the electromagnet first draws them firmly into engagement to more reliabl furnish current to the winding, and therea ter they are quickly and forcibly separated by a blow from the actuating mechanism as, for instance, when the springs become fullystressed thereby.

In electric` clocks of this kind, the pressure of the electromagnetically-operative actuating mechanism on the escapement of the .movement is removed when the spring is being rewound, So the briefness of each rewinding period, the escapement becomes subject in those periods to unsteady movements afecting the accu-` racy of the clock. In accordance^with this part of my invention, the pressure of the actuating mechanism on the escapement is replaced, while the spring isabeing rewound, bfy an interwinding mechanism comprising, idesired, a member adapted to engage the .escapement yto exert pressure on it, and

meansv forl forcing the member into engaging position while the spring is being rewound, Preferably, this member is a yieldable'arm toQ preclude shock to the escapement, and is'carried by an armature of the electroma'gnet that serves to rewind the spring. hus whenever the electroma et is energized to rewind'the spr1ng, the 1 terwinding mechanism is engaged with the esthat, notwithstanding capement to replace .thereon the pressure of the actuating mechanism.

In the accompanying drawings illustrating the preferred embodiment of the invention,` in application, as an example, to an automobile clock which is devoid of the usual operating spring 'but is provided with comparatively lighty springs adapted to be retensioned at brief intervals.

Figure 1 is a rear view, partly broken away and partly diagrammatic, particularly showing the electromagnetically.- operative actuating mechanism g" Fig. 2is a diagrammatic View of that mechanism at the beginning ofthe rewinding movement; Fig. 3 is a similar-diagrammatic view at the end of the rewinding movement; and Figs. 4, 5 and 6 are sections on lines 4 4, 5-'5 and 6 6, respectively, of Fig. 1.

The clock is of circular outline having a case 1 of non-magnetic material adapted to be fastened by screws to the dash board of an automobile. The movement includes an escapement 2, a reset mechanism 3, and an arbor 4 on which is fast a ratchet 5.

Surrounding the movement is an electromagnet having an iron core of trough section comprising a base'6 and the two flanges 7 vdirected outwardly of the movement and forming continuous poles around its ou'ter circumference, so that substantially all the magnetic lines of force external of the core extend between thexpoles in a direction away from the movement to screen it magnetically. The member 8 is journaled on the arbor 4, and carries Vdiametrically-disposed pawls 9 spring pressed into engagement -With the ratchet 5. This member is attached at diametrically opposite points to the springs 10 which extend in opposite directions from fixed connections at 11. By means of the rods 12, thismember is connected atdiametrically opposite points with the armatures 13pivoted to the core at diametrically opposite points and extending in opposite directions, up and down, from their pivots. The' member 8 is substantially balanced with respect to the arbor 4, so as to remain in stability -in whatever position it mayhave.

As a result of the balanced arrangement noted, a blow or vibration impartedto any part of the case l is transmitted equally to' opposite points of the ratchet 5 through the diametrically disposed pawls 9, thus neutralizing the ei'ect on the'escapement 2 of the movement and precluding interference with the accurate operation thereof.

`The electromagnet has an energizing Winding 14 wound around the base 6 between the flanges 7 of the core. One terminal of this winding is connected to a battery 15, and the other terminal is connected through the spring arm '16 forming the movable electric contact in coperation with the stationary electric contact 1'7. This spring arm 16' also carries the armature 18 normally held by the arm in a position away from the flanges 7 of the electromagnet core. The spring arm 16 is also fast with the outer end f the arm 19 of the bell crank lever pivoted at 20 and having its other arm 21 extending downwardly between prongs 22 and 23 of member 8, so as to lie in the path of movement of those prongs.

The electromagnet core is also provided with an armature 24 pivoted at 25 and carrying a flat spring arm 26 resting on the teeth of the ratchet 5 but adapted to be forced into engagement therewith when attracted by the core. This interwinding mechanism functions while the springs 10 are being retensioned, to replace at that time the pressure of those springs exerted through the pawls 9 on the ratchet and thereby eliminate the unsteady action of the escapement that would result if pressure on it were not maintained.

Starting with the springs fully extended vas shown in Fig. 3, the operation of the clock is as follows: As the springs contract in turning the member 8 anticlockwise, the pawls 9 maintain pressure on the ratchet 5 to' drive the e'scapement 2 and advance the hands of the clock, the electric contact 16 moving Vtoward contact 17 through the medium of the bell crankV lever 19, 211until engaged therewith, as shownin Fig. 2. Thereupon, the circuit betweent the battery 15 and the winding 14 is closed and the electromagnet energized. The armatures 13 are quickly and forcibly attracted into engagement with the anges 7 of the core, turning the member 8 in a clockwise Adirection and extending the springs 10 as the pawls 9 slip backward over one or more teeth ofv the ratchet. At the Sametime, the armature 18 vis attracted to the flanges 7 and thereafterholds the movable contact 16 in irm'engagement with the contact 17, un-

til at such time that the prong 22l strikes the arm 21a blow to positively disengage the driving pressure ofthe pawls 9 on the lratchet with the pressure'exerted by the core of the electromagnet on the. armature 24 v through the yieldable arm 26.

As soon as the electric contacts 16, 17 are disengaged, the magnetic attraction between the anges 7 of the core and the armatures 18 and 24 ceases. .This cycle is repeated at brief intervals, every minute or so, de-

mechanism there or Aelectromagnetically operative pending upon the movement of contact 16 etweenopen and closed positions with respect to the co erative contact 17.

Having thus escribed my invention, what I claim lis:

1. In an electric clock, amovement, and

electromagnetically operative actuating' mechanism therefor including an electro magnet havin an annular core of trough form surroun ing the movement.

5. In an` electric clock, a movement, and electromagnetically operative actuating Amechanism therefor including an electromagnet having a continuous core of trough form with its the movement.

v6. In an electric clock, a movement and electromagneticall operative actuating mechanism there or including an electromagnet having a continuous core of trough form which surroundsthe movement and which has its poles directed outwardly of the movement. c

7. In an electric clock, a movement, and electromagneticall operative actuating including an electromagnet having an annular core which'surrounds the movement and which lis of trough form with its flanges directed outwardly out of its base.

8. In an electric clock, a movement, and actuating mechanism therefor including an electromagnet having a continuous core of trough form surrounding the movement and containing an energizin wlnding.

9. In an electrlc c ock, a movement, and electromagnetically operative actuating mechanism therefor including springs and two oppositely-pivoted armatures connected to said springs and-'adaptedto stress them when attracted by the core of the electromagnet for subsequently actuating the movement.

10. In an electric clock, a movement, an electromagnet having a. core and diametrically-disposed oppositelypivoted armatures, and springs connected to the airnatures and to the movement, said armatures being poles directed outwardly of` whereby adapted to stress the springs when attracted by the core of the electromagnet for subsequentl actuating the movement.

11. n an electric clock, a movement having an'arbor and a ratchet fast thereon, a member journaled on the arbor carrying diametrically-disposed pawls engaging the ratchet, oppositely-disposed springs connected to said member at diametrically-opposite points, and an electromagnet having a core and diametrically-disposed oppositelypivoted armatures connected at .their freeends to said member for stressing saidy springs when attracted by the core.

12. In an electric clock, a movement havl ing an arbor and a ratchet fast thereon, a

substantially balanced member journaled on the arbor carrying diametrically-disposed pawls engaging. the ratchet, oppositely-disposed springs connected to said member at diametrically-opposite points, and an elec-Y tromagnet having .a core and diametricallydisposed oppositely-pivoted armatures connected at their free ends to said member for stressing said springs when attracted by the.

core.

13. lIn an electric clock, amovement, and electromagnetically operative actuating mechanism therefor including an energizing winding, a source of electric current, circuit connections between said source and said winding including electric contacts, a pivoted arm on which `one of said contacts is mounted in coperation with the other, and

means responsive to said actuating mechanism for striking said pivoted arm while the contacts are closed to quickly separate them.

14. In an electric clock, a movement having an arbor with' a ratchet mounted thereon, a member carrying a pawl for engagement with said ratchet, an electromagnet having anenergizing winding and an armature connected to said member, a sourceof electric current,circuit connections between said source and saidwinding including electric contacts, apivoted arm carrying one of said contacts in coperation with the other and extending into the 'path of movement of said member, the construction and arrangement being such that, upon attractionof the armature resulting from the closure of said contacts, said member is moved by the armature and strikes the pivoted arm to quickl separate the contacts.

15. n an electric clock, a -movement hav- Ving an Aescapement, electromagnetically-operative actuating mechanism therefor including an electromagnet and a spring adapted to be rewound intermittently, an

vintcrwinding mechanism including an 4`arm engageable with the escapement and forming -an armature of the electromagnet,

when the electromagnet is energi'zed to rewind the spring, the interwindadaptedpto be retensioned intermittently, an interwinding mechanism including a yieldable armcarried by an armature of the electromagnet for engagement with .the escapement While the springjs being retensioned. In testimony whereof I affix my signature.

' LOUIS E. SHAW. 

